Distributor for use in refrigerating systems



Nov. 22, 1927.

W. G. E. ROLAFF DISTRIBUTOR FOR USE IN REFRIGERATING SYSTEMS Filed Jan. 10, 1924 fit .6".

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PATENT OFFICE.

WALTER G. E. ROLAFF, OF ST. LOUIS, MISSOURI.

DISTRIBUTOR FOR USE IN BEFRIGERATING SYSTEMS.

Application filed January 10, 1924. Serial No. 685,470.

This invention relates to refrigerating machines, and has for itsgeneral object the provision of a distributor for the refrigerant to be used in the system in place of the ordinary expansion valve.

A further object of the invention relates to the novel construction of the distributor, including the provision of means for maintaining the pressure in the distributor at a point sufiiciently lower than the pressure 111 the condenser to permit the ready flow of the refrigerant through the distributor.

Still further objects of the invention relate toa novel combination of elements constituting a refrigerating system, as a whole, resulting from the incorporation in such system of my improved distributing"device.

The invention is illustrated in the accompanying drawings, in which' Figure 1 is a sectional view illustrating my improved refrigerant distributor as con-' structedfor use on the highpres's'ure side 7 of a refrigerating system; and

Figure 2 is a diagrammatic view illustrating a refrigerating system having my distributor embodied therein.

In order that the relation of my invention to a refrigerating system, and the advantages to be derived from its use, may be better understood, I will first state briefly the disadvantages in prior arrangements which it is the main purpose of the present invention to overcome.

As stated above, my distributor is de signed to replace the ordinary automatic expansion valve, which, in one form or another, has heretofore been used in practically all mechanical refrigerating systems. The

expansion valve employs a diaphragm which,

1n all lnstallations of which I am aware, 1s

so located in the system as to, be susceptible to changes in pressure on the low side of the system, This diaphragm ordinarily works a needle valve, so that when the pressure ,on the low side reaches acertain point, the diaphragm is depressed against a spring and the valve is closed, shutting off v the flow of the refrigerant. An adjustment of the spring makes it possible to set the expansion valve to work at any given pressure.

The-expansion valve, as soused, has two pronounced disadvantages. The first of these is its inability to adapt itself to varying changes of temperature to produce the highest refrigerating efficiency in operation.

To make this clear, it should be understood that, for any given temperature in the chamber or enclosure cooled, for example, an icebox, there is a corresponding pressure at which the liquid refrigerant will be capable of absorbing the largest quantity of heat. To obtain the best possible results from an expansion valve, therefore, it should, theoretically, be adjusted every minute of the day to operate at that pressure which will ideally correspond to the temperature in the expansion coil. Such frequent adjustment 1s,'of course, wholly impracticable. In practice, therefore, the valve is simply set to operate at a given pressure.- As a result, there is only 'one temperature in the expansion coil for which such setting is ideal. To the extent that the temperature fluctuates above or below that point, the system will decrease in efficiency.

The second disadvantage of the expansion valve is that it cannot prevent't-he flow of gas1 from the compressor to. the expanslon col to go over from time to time. This, of course, impairs the efliciency of the system, since the gas has only a' fraction of the refrigerating ability that is possessed by the liquid.

To overcome the above disadvantage, 1 provide a distributor in which is always constantly maintained a body of liquid refrigerant, which eifectually prevents any gas, that may have escaped condensation in the condenser, from reaching thevalve and, therefore, from going over into the low side. This distributor is operated bythe flowof the liquid refrigerant and it is entirely independent of the pressure on the low side. This pressure, therefore, since it is not throttled by the distributor, as it would be with an expansion valve, will automatically respond to changes of temperature in the expansion coil, so that whatever the temperature, the pressure will always be at the ideal point for maximum absorptionof heat.

I will now describe the invention in detail,

\Vhen all the liquid has been passed over into the low side, gas will be permitted referring to the accompanying drawing, in

which the numeral 1 (Figure 2) indicates,

conventionally a compressor from which a pipe 2 leadsito a condenser 3, which communicates with a receiver it for the liquid refrigerant. From this receiver, apipe 5 leads to my improved distributing device6,

and from this distributor a pipe 7 leads; to the bottom of an expansion coil 8 which, in

practice, is located in the ice-box or. other enclosure to be cooled. From the top of the expansion coil, a pipe 9 leads back to the suction side of the compressor.

' Referring now to Figure 1, where the distributor is shown on an enlarged scale, the numeral 10 indicates the casing of the distributor, into the bottom of which, at one end, leads the pipe 5, and, at the other end, the pipe 7, previously referred tb.

The casing 10 provides a chamber 11, and located within this chamber is a float valve comprising a hollow float 12, having at one end an arm 13, which is pivotally mounted refrigerant from the chamber 11 to the redescribed,

cess 19, and thence through the opening in the valve seat 20 when the valve, 18' is raised. In the operation of the device as thus far through the pipe 5 into the chamber 11 of thedistributor, and when it reaches a certain height therein, will raise the float 12,

which will operate to lift the needle valve 18 from its seat and permit the liquid refrigerant to pass through the pipe 7 to the 1 expansion coil 8. The needle valve, therefore, will open only when there is a sufficient uantity of liquid in the distributor to raise t e float to which the valve is attached.

Therefore, there is constantly maintained in l the chamber 11 a body of liquid refrigerant,

and this, as stated above, will prevent passage of any gas, that may have escaped condensation in the condenser .3, from reaching the needle valve and passing over into the -low side of the system. In this way. the

disadvantage, as respects the passage of gas a to the low side which obtains in the use of an expansion valve, as above alluded to, is

overcome. 1

Again, my distributor works on the prin ciple of the flooded system. It operates to always maintain a certain quantity of liquid in the expansion coil 8. As fast as the re- 1 frigerant gasifies. it is compressed, condensed, and. in the form of liquid; again passed through the distributor into the ex pansion coil. This flow of liquid. as will be obvious, is entirely independent of the pressure on the low side; and this pressure will automatically respond to changes in temperature, so that Whatever the temperature the liquid refrigerant passes" at the expansion coil, the pressure will alwaysbe atthe ideal point for maximum expansion.

As thus far described, the refrigerating I system, including the distributor, would only operate in installations in which the distributor 6'is located below the condenser. For obvious reasons, the distributor should be placed as close as possible to the expansion coil 8, and since, in most commercial To overcome this obstacle, I provide a gas relief tube for maintaining the pressure in.

the distributor at a point sufficiently lower than the pressure in the condenser to permit the upward travel of the refrigerant. This tube is indicated in the drawing by the numeral 22 and, as shown, leads from near the top of chamber 11 through the valve block 16 and into communication with the pipe 7, or low side of the system. The tube 22 furnishes an avenue of escape for the gas that is generated at the surface of the liquid in the distributor,such gas being short-circuited past the valve into the low side pipe. It should be understood, however, that the only gas that escapes through the tube 22 is the gas generated in the distributor itself, which is very minute in quantity and not suflicient to noticeably impair the efficiency of the sys tem when, such gas is permitted to escape into the low side. In other words, none of the gas that has escaped condensation in the condenser ever reaches the relief tube 22, because it is prevented from doing so by the body oaf liquid that is always maintained in the bottom portion of the distributor.

It should be stated, in conclusion, that the position of the parts of the system, as illustrated in Figure 1, ismerely for convenience of illustration, and does not necessarily represent the relative arrangement of the parts of the system as would obtain in actual practice. Also, while I have illustrated, and.

prefer'to use, afloat valve for automatically controlling the flow of therefrigerant to the expansion coil, the invention, in its broad aspects, is not limited to the use of such a valve.

I claim:

'1. In a refrigerating system, involving a compressor, condenser and expansion coil, a

distributor located between the condenser and expansion coil and comprising a chamber communicating with the condenser and having a valve-controlled outlet leading to the expansion coil, a float in said chamber connected with said valve and acting to control the same according to the rise and fall of the liquid refrigerant in said chamber, and means for by-passing gas from said chamber around said valve to the low side of the system.

2. In a refrigerating system, involving a compressor, condenser and expansion coil, a distributor located between the condenser and expansion coil and comprising a chamber communicating with the condenser and having a valve-controlled outlet, and a gasescape tube leading from near the'top of said chamber around said valve to the outlet to the expansion coil for by-passing gas from said chamber to the loW side of the system.

3. In a refrigerating system, involving a compressor, condenser and expanslon coil, a distributor located between the condenser and expansion coil and comprising a chamber communicating with the condenser and having a valve-controlled outlet leading to the expansion coil, means .ufOl automatically regulating the passage of liquid from said chamber to the expansion coil through the medium of the quantitative flow of the liquid refrigerant from the condenser into said chamber, and means for by-pr ssing vaporized gas from said chamber around said valve to the low. side of the system.

4t. In a refrigerating system involving a compressor, condenser and expansion coil, a distributor for liquid refrigerant located between the condenser and expansion coil comprising a chamber communicating with the condenser and having a valve-controlled outlet leading to the expansion coil, and means for maintaining the pressure in said chamber below the pressure in the condenser.

5. In a refrigerating system involving a compressor, condenser and expansion coil, a distributor for liquid refrigerant located between the condenser and expansion coil comprising a chamber communicating with the condenser and having an outlet leading to the expansion coil, an automatic valve for controlling the flow of liquid refrigerant from said chamber to the expansion coil, and means for maintaining the pressure in said chamber below the pressure in the condenser.

6. In a refrigerating system involving a compressor, condenser and expansion coil, a

distributor for liquid refrigerant located between the condenser and expansion coil comprising a chamber communicating With the condenser and having a valve-controlled outlet leading to the expansion coil, and means affording constant communication between the interior of said chamber above the level of the liquid refrigerant therein and said expansion coil for by-passing gas from said chamber around said valve to the low side of the system, whereby to maintain the pressure in said chamber below the pressure in the condenser.

In testimony whereof, I have hereunto set my hand.

WALTER G. E. ROLAF F. 

